1. Field of the Invention
This invention relates to a microwave ion source, and more particularly, a microwave ion source causing electron cyclotron resonance between a microwave and a magnetic field and generating ions by means of a microwave discharge.
2. Description of the Prior Art
Ions generated in a discharge chamber are extracted from the discharge chamber by the electric field of an ion extraction electrode through an ion extraction aperture. However, because some ions move in a direction deviating from the ion-extracting direction, there develop some problems by which their quality of being parallel with each other is deteriorated and the efficiency of making effective the ion current is reduced.
Heretofore, disclosure of microwave ion sources has been made by "N. Sakudo, K. Tokiguchi, H. Koike and I. Kanomata, Rev. Sci. Instrum., Vol. 48, No. 7, p. 762-766, July, 1977" and "N. Sakudo, K. Tokiguchi, H. Koike and I. Kanomata, Inst. Phys. Conf. Ser No. 54: chapter 2, p. 36-41, 1980".